Arrays,String.......

1. Programming in C (Part 2)
BY:SURBHI SAROHA

2. SYLLABUS
 Sequencing
 Alterations
 Iterations
 Arrays
 String processing
 Subprograms
 Recursion

3. Sequencing
 In C programming language, there are 256 numbers of characters in character set.
 The entire character set is divided into 2 parts i.e. the ASCII characters set and the extended ASCII
characters set.
 But apart from that, some other characters are also there which are not the part of any characters set,
known as ESCAPE characters.
// C program to illustrate
// a escape sequence
#include <stdio.h>
int main(void)
{
printf("My mobile number "
"is 7a8a7a3a9a2a3a4a0a8a");
return (0);
}


4. List of Escape Sequences

5. Alterations and iterations
 When we use the term iteration, we are usually talking about loops.
 For, while, and do...while loops in C are loops that will execute as long as a condition is true.
 Iteration is one of the reasons that computer programs exist in the first place.
 You shouldn't need to manually calculate a value 1000 times over.
 Let the program do the heavy lifting!
 Iteration introduces the risk of an infinite loop.
 The condition is always true, and the program will run forever unless stopped (or the computer
crashes)! Even though the risk is there, with proper debugging and testing, it can be avoided.

6. Arrays
 Arrays a kind of data structure that can store a fixed-size sequential collection of elements of the
same type.
 An array is used to store a collection of data, but it is often more useful to think of an array as a
collection of variables of the same type.
 Instead of declaring individual variables, such as number0, number1, ..., and number99, you
declare one array variable such as numbers and use numbers[0], numbers[1], and ...,
numbers[99] to represent individual variables.
 A specific element in an array is accessed by an index.
 All arrays consist of contiguous memory locations.
 The lowest address corresponds to the first element and the highest address to the last element.

7. Array

8. Arrays
 Declaring Arrays
 To declare an array in C, a programmer specifies the type of the elements and the number of elements
required by an array as follows −
 type arrayName [ arraySize ];
 This is called a single-dimensional array. The arraySize must be an integer constant greater than zero
and type can be any valid C data type. For example, to declare a 10-element array called balance of
type double, use this statement −
 double balance[10];
 Here balance is a variable array which is sufficient to hold up to 10 double numbers.

9. EXAMPLE
 #include <stdio.h>
 int main () {
 int n[ 10 ]; /* n is an array of 10 integers */
 int i,j;

 /* initialize elements of array n to 0 */
 for ( i = 0; i < 10; i++ ) {
 n[ i ] = i + 100; /* set element at location i to i + 100 */
 }


10. Cont….
 /* output each array element's value */
 for (j = 0; j < 10; j++ ) {
 printf("Element[%d] = %dn", j, n[ j] );
 }

 return 0;
 }

11. OUTPUT
 Element[0] = 100
 Element[1] = 101
 Element[2] = 102
 Element[3] = 103
 Element[4] = 104
 Element[5] = 105
 Element[6] = 106
 Element[7] = 107
 Element[8] = 108
 Element[9] = 109

12. String processing
 C supports a large number of string handling functions in the standard library "string.h".
 Strings handling functions are defined under "string.h" header file.
 #include <string.h>
 #include<stdio.h>
 int main() {
 char name[30];
 printf("Enter name: ");
 gets(name); //Function to read string from user.
 printf("Name: ");
 puts(name); //Function to display string.
 return 0;
 }

13. String functions

14. Subprograms
 A Subprogram is a program inside any larger program that can be reused any number of times.
 General Subprogram Characteristics
 A subprogram has a single entry point.
 The caller is suspended during execution of the called subprogram. “Only one subprogram in
execution at any given time.”
 Control always returns to the caller when the called subprogram’s execution terminates

15. Cont…
 Basic Definitions
 A subprogram definition is a description of the actions of the subprogram abstraction.
 A subprogram call is an explicit request that the called subprogram be executed.
 A subprogram is said to be active if, after having been called, it has begun execution but has not
yet completed that execution.
 The two fundamental types of the subprograms are:
 Procedures
 Functions

16. Recursion
 Recursion is the process of repeating items in a self-similar way.
 In programming languages, if a program allows you to call a function inside the same function,
then it is called a recursive call of the function.
 void recursion() {
 recursion(); /* function calls itself */
 }
 int main() {
 recursion();
 }

17. Cont…
 The C programming language supports recursion, i.e., a function to call itself.
 But while using recursion, programmers need to be careful to define an exit condition from the
function, otherwise it will go into an infinite loop.
 Recursive functions are very useful to solve many mathematical problems, such as calculating the
factorial of a number, generating Fibonacci series, etc.

18. The following example calculates the factorial of a given number
using a recursive function −
 #include <stdio.h>
 unsigned long long int factorial(unsigned int i) {
 if(i <= 1) {
 return 1;
 }
 return i * factorial(i - 1);
 }
 int main() {
 int i = 12;
 printf("Factorial of %d is %dn", i, factorial(i));
 return 0; }
 Factorial of 12 is 479001600

19. THANK YOU 